Snapping knee caused by a popliteomeniscal fascicle tear of the lateral meniscus in a professional Taekwondo athlete

A 19-year-old male professional Taekwondo athlete presented with a 2-year history of pain-free snapping of his right knee. He reported that his right knee joint gave way during games and training and that he could induce pain-free snapping between the proximal-to-fibular head and the lateral knee joint line. None of these physical findings suggested a meniscal pathology or ligamentous instability. Routine radiographs were normal. Magnetic resonance imaging of his right knee joint showed that the shape of the lateral meniscus was normal, and no lateral meniscus tears existed. On arthroscopic examination, popliteal hiatus view showed a posterosuperior popliteomeniscal fascicle tear between the posterior horn of the lateral meniscus and the posterior joint capsule just posteromedial to the popliteus tendon. With medial traction by probing, this popliteomeniscal tear made visible the significant subluxation of the posterior horn of the lateral meniscus to the center or anterior half of the tibial plateau. Based on the diagnosis of a posterosuperior popliteomeniscal tear of the right knee, Fast-Fix (Smith & Nephew, Andover, Massachusetts) was used for the direct repair of the peripheral portion of the lateral meniscus and joint capsule, targeting the popliteomeniscal junction. At 24 months postoperatively, the patient was performing athletic exercises relevant to his profession and was taking part in Taekwondo games, with no pain or recurrence of snapping. To the authors' knowledge, this is the first report of snapping of the lateral aspect of the knee due to a popliteomeniscal fascicle tear.     

Anatomy of the posterolateral aspect of the goat knee.

The purpose of this study was to determine the anatomy of the posterolateral aspect of the goat knee for future in vivo studies using a goat model to examine the natural history of posterolateral knee injuries. Twelve non-paired, fresh-frozen, adult goat knees were dissected to determine the anatomy of the posterolateral corner. The main posterolateral structures identified in the goat knee were the lateral collateral ligament, the popliteus muscle and tendon, popliteomeniscal fascicles, and the lateral gastrocnemius muscle. The lateral collateral ligament was extra-articular and coursed from its proximal attachment, located posterior and proximal to the lateral epicondyle, to its distal attachment on the lateral aspect of the fused proximal tibiofibula. The popliteus muscle attached to the medial edge of the posterodistal tibia, traveled anterolaterally, became intra-articular at its musculotendinous junction, and attached to the lateral femur just distal to the lateral epicondyle. Distinct popliteomeniscal fascicles attached the lateral meniscus to the popliteus muscle and tendon, and a fascial attachment from the musculotendinous junction of the popliteus muscle coursed to the lateral tibial plateau. This study provided information on the structures present in the posterolateral aspect of the goat knee and enhanced our understanding of their relationships to analogous structures in the human knee. This information is important to enable future development of potential models of the natural history of posterolateral knee injuries and also to test surgical techniques and the in vivo effects of these injuries on cruciate ligament reconstructions.     

The popliteus tendon

The posterior aspect of forty cadaver knees was dissected to determine the proximal insertion of the popliteus tendon, particularly its relationship to the lateral meniscus. Thirty-three (82.5 per cent) of the specimens demonstrated no major attachment of the popliteus tendon to the lateral meniscus. Eight specimens were from bilateral dissections and revealed no major asymmetry. On the basis of these dissections, we found no evidence that the popliteus tendon has a role in the retraction and protection of the lateral meniscus.     

Ranawat Award paper. Effect of selective lateral ligament release on stability in knee arthroplasty

The current authors evaluated a fundamental approach to balancing the lateral ligaments of the knee that begins with aligning the implants correctly in flexion and extension, proceeds to assessing stability in flexion and extension, and concludes with releasing tight structures based on their function throughout the arc of flexion. Seventeen knees from cadavers were used to evaluate stability at various degrees of flexion after total knee arthroplasty, and then stability was reevaluated after release of selected ligaments. The iliotibial band and posterior capsule were effective lateral stabilizers only in full extension. The lateral collateral ligament had a major stabilizing effect throughout the arc from 0 degrees to 90 degrees flexion. The iliotibial band and popliteus tendon and posterolateral corner capsule had little effect when the other ligaments were intact. When tested in the absence of the other lateral ligaments, the popliteus tendon and posterolateral corner capsule had significant stabilizing effects throughout the flexion arc. The popliteus tendon exerted its effect mostly from 60 degrees to 90 degrees flexion. The posterolateral corner capsule was effective mostly at 0 degrees to 30 degrees flexion. The iliotibial band had a significant stabilizing effect from 0 degrees to 30 degrees flexion.     

Bilateral symptomatic snapping biceps femoris tendon due to fibular exostosis

We present an unusual case of an athletic 17-year-old male cyclist with bilateral chronic dislocating biceps femoris tendons. On flexion of the knee, the biceps tendon subluxed over a large exostosis, creating a snapping sound. Snapping of tendons is common around the hip, ankles, shoulder, and elbow, but rare at the knee. When it does occur, snapping about the knee can be due to discoid meniscus, rheumatoid nodules, synovial plicae, iliotibial band syndrome, congenital snapping knee, and snapping tendons. Research revealed only 5 previous cases due to subluxation of the biceps femoris tendon. The case we present is the only one due to an exostosis, as well as the only one that required bilateral surgical repair. The patient presented when his pain became significant enough to interfere with his ability to continue competitive cycling.     

Arthroscopic treatment of popliteus tendon dysfunction following total knee arthroplasty

Following total knee arthoplasty, the popliteus tendon may cause a “snap” when it rolls over a retained lateral femoral condylar osteophyte or when it subluxates over the posterior condyle of the femoral component. When this condition is painful and fails to respond to conservative treatment, arthroscopic release of the popliteus tendon has been beneficial     

Development of the popliteomeniscal fasciculi in the fetal human knee joint

Purpose: The purpose of this study is to better understand the function of the popliteomeniscal fasciculi and their relationship to the popliteus tendon and the lateral meniscus by describing these structures during embryonic development. Type of Study: Anatomic dissection and histologic evaluation. Methods: Twelve fresh-frozen lower extremity specimens (6 paired limbs) from second and third trimester human fetuses were obtained from spontaneous abortions. Each specimen was fixed in formalin and decalcified in 9.0% nitric oxide. The specimens were prepared by removal of all skin and most of the soft tissues before dissection of the lateral meniscus, parts of the posterolateral joint capsule, and the popliteus tendon and muscle. The right-side specimens were sectioned in the transverse plane, and the left-side specimens in the coronal plane. Histologic sections were prepared with H&E and Masson’s trichrome stains. Light microscopy was used to evaluate the lateral meniscal attachment, with detailed attention to the popliteomeniscal fasciculi. Results: The close interrelationship of lateral meniscus and popliteus tendon, especially during embryologic development, does give a better understanding how the fasciculi stabilize the lateral meniscus and allow the popliteus tendon to function as a retractor of the lateral meniscus. The fasciculi consist of 3 layers including a dense collagen layer, a vascular layer, and a synovial or capsular layer. Conclusions: During embryologic development, the fasciculi appeared to provide a vascular supply to the lateral meniscus adjacent to the popliteal hiatus where the meniscus is devoid of capsular attachments.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 1 (January), 2001: pp 14–18     

The anatomy of the posterolateral aspect of the rabbit knee.

The purpose of this study was to determine the anatomy of the posterolateral aspect of the rabbit knee to serve as a basis for future in vitro and in vivo posterolateral knee biomechanical and injury studies. Twelve nonpaired fresh-frozen New Zealand white rabbit knees were dissected to determine the anatomy of the posterolateral corner. The following main structures were consistently identified in the rabbit posterolateral knee: the gastrocnemius muscles, biceps femoris muscle, popliteus muscle and tendon, fibular collateral ligament, posterior capsule, ligament of Wrisberg, and posterior meniscotibial ligament. The fibular collateral ligament was within the joint capsule and attached to the femur at the lateral epicondyle and to the fibula at the midportion of the fibular head. The popliteus muscle attached to the medial edge of the posterior tibia and ascended proximally to give rise to the popliteus tendon, which inserted on the proximal aspect of the popliteal sulcus just anterior to the fibular collateral ligament. The biceps femoris had no attachment to the fibula and attached to the anterior compartment fascia of the leg.This study increased our understanding of these structures and their relationships to comparative anatomy in the human knee. This knowledge of the rabbit's posterolateral knee anatomy is important to understand for biomechanical and surgical studies which utilize the rabbit knee as a model for human posterolateral knee injuries.     

Bilateral PCL hypoplasia resulting in posterior, posterolateral rotatory instability and tears of the lateral meniscus anterior horn

This article describes a case of bilateral sagged knees presenting as posterior, posterolateral rotatory instability with tears of the anterior horn of the lateral meniscus. Each knee had identical tears of the lateral meniscus anterior horn. A 42-year-old woman reported bilateral anterior knee pain and painful instability during running or jarring exercises. She reported no major trauma to her knees. Arthroscopic findings of her right knee revealed a posterior cruciate ligament that looked hypoplastic but was without acute injury, and the anterior horn of the lateral meniscus showed chronic complex tears with some degeneration. Posterior cruciate ligament reconstruction, posterolateral corner sling, and meniscal repair of the lateral meniscus anterior horn was performed on her right knee. Three months later, a similar operation was performed on her left knee. However, menisectomy was performed because the lateral meniscus anterior horn tear was in the junction of the red-white and white zones. At 18 months postoperatively, the patient reported no symptoms and was satisfied with her results. Physical examination showed no joint line tenderness, and posterior stress radiographs on both knees showed grade I posterior instability. She showed no posterolateral subluxaion by supine dial test, and her prone dial test also improved approximately 15° on both knees. Lysholm score was 74 preoperatively and improved to 92 postoperatively.     

Spontaneous isolated rupture of popliteus tendon presenting as locked knee: case study and literature review

Traumatic isolated rupture of the popliteus tendon has been described as a rare cause of haemarthrosis of the knee. There has been only one reported case of spontaneous rupture of the popliteus tendon in the English literature before. We present the case of a 70-year-old lady who had spontaneous rupture of the popliteus tendon without history of significant trauma. She presented with a painful locked knee without any features of instability. The diagnosis was made on arthroscopy of the knee and she made a complete recovery after partial excision of the torn tendon. Our literature review looks at treatment options in relation to best functional outcome.     

Calcific tendinitis of popliteus tendon: a case report and review of literature

A 63-year-old woman presented with a 3-week history of worsening right knee pain. She was fully unable to bear weight and denied any history of trauma, locking or giving way. On examination, she was systemically well with posterolateral joint line tenderness and a reduced range of movement. Blood tests and a joint aspirate were normal. Radiographs reported no fracture, but suggested a loose body in the lateral gutter of the knee. She was discharged with analgesia and physiotherapy. Subsequent follow-up X-rays demonstrated the opacity in the later gutter to be appearing less dense until it eventually disappeared. This correlated to a progressive improvement in the patient’s pain and range of movement in the knee leading to the diagnosis of acute calcific tendinitis of the popliteus tendon. This case report suggests that calcifying tendinitis of popliteus tendon should be considered in the differential diagnosis of acutely painful knee. The case demonstrates that the natural history of calcifying tendinitis of popliteus is similar to that in supraspinatus and that conservative treatment will eventually resolve the symptoms.     

Diagnosis of popliteus tenosynovitis by ultrasound

Pain around the lateral aspect of the knee is a common occurrence, and precise diagnosis may be difficult on clinical examination alone. Routine imaging modalities include plain radiographs, Technitium 99m bone scanning, computed tomography, and magnetic resonance imaging. Ultrasound has been little used in the investigation of knee pathology. The authors present a case of recurrent tenosynovitis of the popliteus tendon in which the diagnosis was finally (after 22 years) made using ultrasound. The authors suspect that this condition may be more common than previously believed and that it may be misdiagnosed as meniscal pathology. The authors recommend the use of ultrasound imaging in swellings around the lateral aspect of the knee, avoiding unnecessary, expensive or invasive investigations. J Orthop Sports Phys Ther 1992;16(2):58-59.     

Assessment of a goat model of posterolateral knee instability

The development of an in vivo animal model of posterolateral knee instability is desired for devising effective interventions for this injury. Sequential sectioning of the popliteus tendon, lateral collateral ligament, and lateral capsule was done in cadaveric goat knees to create knee joint instability, followed by in vivo studies (Studies 1 and 2) of 7 and 3 months duration, respectively. In Study 1, the popliteus tendon and lateral collateral ligament were sectioned; in Study 2, these structures as well as the lateral joint capsule were sectioned. Biomechanical testing and histological assessments were done to determine the severity of the instability and the morphological changes. Sectioning the lateral collateral ligament and popliteus tendon (Study 1) resulted in a significant increase in varus instability at 90°. Sectioning the lateral collateral ligament, popliteus tendon, and lateral capsule (Study 2) resulted in significant varus instability at 30°, 60°, and 90°, and significant internal–external rotation at 60° and 90°; however, the lesions of osteoarthritis in the operated knees were similar to those in unoperated control knees. This study confirms that posterolateral knee instability can be created in a goat model, but we were unable to demonstrate lesions of osteoarthritis that were of sufficient severity to allow evaluation of disease reduction in future intervention procedures. Future studies will determine if further manipulation of the model results in sufficient morphological changes to allow its use in the assessment of intervention strategies. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:651–659, 2008     

吻合血管髂胫束移植修复跟腱缺损

目的探讨带血管的髂胫束游离移植修复跟腱缺损的术式及疗效. 方法在解剖观测髂胫束的血供来源及膝上外侧动脉的起源、走行、分支、分布及吻合的基础上,进行手术设计.1999年9月～2003年1月应用吻合血管的髂胫束修复长段跟腱缺损6例,其中单纯跟腱缺损4例,复合跟腱缺损2例,缺损长度6～11 cm. 结果膝上外侧动脉起自动脉,向外上走行分为升、降支.升支发出肌支和髂胫束穿支;膝上外侧动脉升支与膝最上外侧动脉在股外侧肌内吻合后穿出股外侧肌形成肌皮穿支.降支发出肌支、3～5支股骨外侧髁骨膜支及髂胫束穿支.术后供、受区创面均一期愈合.随访6个月～3年8个月个月,Thompson征阴性,双、单足提踵试验阴性.无跟腱再断裂、跟区皮肤破溃等并发症发生. 结论根据膝上外侧血管的分支、分布及吻合特点,吻合血管的髂胫束游离移植是修复跟腱缺损的一种较好的治疗方法.     

误诊为半月板损伤的弹响膝122例分析

目的探讨误诊为半月板损伤患者弹响膝的发生机制、临床表现、诊断和关节镜治疗。方法回顾性分析122例术前误诊为半月板损伤的弹响膝患者资料,所有患者均接受膝关节镜手术。分析不同病因导致膝关节弹响的部位、响度、发生频率、镜下表现,最终评价关节镜手术疗效。结果许多疾病均可出现膝关节弹响,最常见原因为半月板损伤,其次是关节内游离体、软骨病变、滑膜病变、髌股关节紊乱、韧带及肌腱损伤等。其弹响各有特点,关节镜诊治后91．8％弹响症状完全消失,少数患者残余部分症状？结论膝关节弹响来源多样,半月板源性的弹响最为常见。掌握弹响特点有助于术前正确诊断,提高手术疗效,避免过度医疗。关节镜手术是诊治弹响膝的金标准。     

The popliteus tendon and its fascicles at the popliteal hiatus: gross anatomy and functional arthroscopic evaluation with and without anterior cruciate ligament deficiency

Gross anatomical dissection of the popliteus muscle, the popliteus tendon and its fascicles, and their relation to the lateral meniscus was carried out in 14 human adult cadaver knees. Videoarthroscopy through an anterolateral portal was then used to assess and document the functional integrity of the popliteus tendon and its fascicles forming the popliteal hiatus in vivo. A control group of cruciate ligament intact knees (n = 107) was compared with an anterior cruciate ligament (ACL)-deficient group (n = 68). The incidence of structural lesions of the popliteus system was 18.7% in the control knees, 95% in 40 acute ACL disruptions, and 85.7% in 28 chronic ACL-deficient knees. Functional arthroscopic evaluation of the popliteus tendon and its fascicles blending into the lateral meniscus was a valuable adjunct in assessing secondary posterolateral restraints in acute and chronic ACL-incompetent knees.     

An interesting case--calcific tendinitis of the popliteal tendon]

We present a case of a calcifying tendinopathy of the lateral aspect of the knee. A 72 years old woman developed an acute calcifying tendinitis in the region of the popliteus tendon of the left knee. In the course of treatment the calcium deposit drained spontaneously into the knee joint. All initially severe clinical complaints died down.     

膝上外侧动脉穿支髂胫束皮瓣的解剖特点与临床应用

目的 探讨膝上外侧动脉穿支髂胫束皮瓣的解剖学基础与临床应用效果.方法 自1999年9月至2009年7月,在40侧经动脉灌注红色乳胶的成人下肢标本上,解剖、观测膝上外侧动脉的起源、走行、分支、分布、吻合以及髂胫束的血供来源,临床应用吻合膝上外侧动脉穿支髂胫束瓣移植5例、髂胫束皮瓣4例.结果 80%(35侧)膝上外侧动脉单独起自腘动脉,起始外径(1.8±0.4)mm.该动脉向外蜿蜒上行分为升、降支,从股外侧肌与股二头肌短头肌之间的股外侧肌间隔穿出形成肌间隙(隔)筋膜皮肤穿支,或与膝上最外侧动脉在股外侧肌内吻合后发出肌皮穿支,供养大腿中下段髂胫束和前外侧皮肤,其中较粗大穿支起始外径(1.0±0.2)mm,并在深筋膜浅层或深层于近端与旋股外侧动脉降支吻合,远端与膝关节网吻合.临床应用9例,其中修复单纯跟腱缺损5例,跟腱伴皮肤缺损2例;修复小腿、足软组织缺损各1例.随访6个月～7年8个月,带血供髂胫束修复跟腱缺损功能恢复良好,4例髂胫束皮瓣全部成活.结论 吻合膝上外侧动脉穿支髂胫束皮瓣是一种新型、简便、实用的复合(软组织)缺损修复方法,适于临床推广应用.     

Combined anterior cruciate-ligament reconstruction using semitendinosus tendon and iliotibial tract

We are reporting the results of a reconstructive procedure designed to decrease anterior tibial subluxation due to disruption of the anterior cruciate ligament. The operation combines both intra-articular and extra-articular methods. The semitendinosus tendon and the iliotibial tract are both routed from opposite directions over the top of the lateral femoral condyle and through the same oblique drill-hole in the proximal part of the tibia: the semitendinosus tendon is passed up through the tibial drill-hole, across the knee joint, over the top of the lateral femoral condyle, and deep to the fibular collateral ligament, and the iliotibial tract is passed deep to the fibular collateral ligament, over the top of the lateral femoral condyle, across the knee joint, and down through the drill-hole. Both grafts are simultaneously pulled tight while the semitendinosus tendon is sutured to the iliotibial tract laterally and the iliotibial tract is sutured to the semitendinosus tendon medially below the drill-hole. The posteromedial and lateral parts of the capsule are advanced to tighten the secondary restraints. One hundred of the first 106 consecutive patients with chronic instability who had this procedure were evaluated using subjective and objective criteria at three to seven and one-half years after surgery. The positive anterior-drawer sign tested at 25 degrees of flexion was eliminated or reduced to 1+ in eighty knees, and the positive pivot shift was reduced to zero or 1+ in ninety-one knees. The objective assessment of isokinetic muscle performance and passive tibial rotation showed significant improvements in strength and normalization of tibial rotation.